Right atrial spontaneous echo contrast and thrombi in atrial fibrillation: a transesophageal echocardiography study

Previous studies have reported the clinical and echocardiographic findings of patients with left atrial spontaneous echo contrast (SEC) and thrombi. We sought to study these characteristics in patients with right atrial SEC and thrombi.

We reviewed 580 consecutive patients from the ACUTE (Assessment of Cardioversion Using Transesophageal Echocardiography) Registry and found 79 patients (14%, aged 67 +/-13 years, 67 male) with transesophageal echocardiography (TEE) findings of right atrial SEC or thrombi (group 1). This group was compared with a control group of 75 consecutive patients (group 2) (aged 68 +/- 13 years, P = not significant; 49 male, P <.005) from the registry with no TEE findings of SEC or thrombi in the left or right atrium.

Atrial fibrillation was present in 60 of 79 group 1 patients (76%). Five right atrial (6%) and 11 left atrial (14%) thrombi were identified. Both left ventricular ejection fraction (39% +/- 16% versus 47% +/- 14%; P =.0005) and presence of right ventricular dysfunction (n = 44 versus 18; P =.0001) differed significantly between groups 1 and 2, respectively. Right atrial area (24 +/- 6 cm(2) versus 22 +/- 6 cm(2); P = .02) was larger in patients in group 1. Left atrial SEC was present in 68 of 79 group 1 patients (86%). Patients with right atrial thrombi and right atrial SEC had a longer duration of arrhythmia (524 +/-812 days versus 147 +/-368 days, P <.05) than patients with right atrial SEC only.

Right atrial SEC has a prevalence of 14% in patients with atrial arrhythmia who undergo TEE-guided cardioversion. Right atrial thrombi are a rare finding and were seen in fewer than 1% (5/580) of patients with atrial arrhythmia. Right atrial thrombi among patients on anticoagulation therapy were not associated with clinically significant pulmonary embolism.